The present invention relates to the synthesis of soluble iron complexes.
U.S. Pat. No. 3,679,377 and U.S. Pat. No. 3,753,675 disclose ammonium, alkali metal, and alkaline earth metal salts of iron complexes of the formulas EQU [Fe.sub.2 (SO.sub.4).sub.2 (OH).sub.3 (H.sub.2 O).sub.5 ].sup.-1 and EQU [Fe.sub.2 (SO.sub.4).sub.3 (OH).sub.2 (H.sub.2 O).sub.5 ].sup.-2
and methods for their production. These iron complex salts are agronomically effective sources of iron. Unfortunately, the methods disclosed in U.S. Pat. No. 3,679,377 and U.S. Pat. No. 3,753,675 release nitrogen oxides (an air pollutant), waste nitrogen (a nutrient), require heating and cooling of a reaction mixture, and are time consuming.